In the existing long term evolution (Long Term Evolution, LTE) release 10 (Release 10, R10), an eNB may notify a UE of a used channel state information-reference signal (Channel State Information Reference Signal, CSI RS) configuration through radio resource control (Radio Resource Control, RRC) signaling, and the UE estimates a corresponding channel according to the CSI RS configuration and feeds back relevant channel state information (Channel State Information, CSI). In an R10 system, generally, each cell identifier corresponds to one CSI RS configuration, and in this case, a CSI RS may be configured for a UE according to a cell identifier.
In a heterogeneous network deployment scenario newly introduced in LTE R11, a same cell identifier corresponds to multiple transmission points (Transmission Point, TP). For example, a low-power remote radio head (Remote Radio Head, RRH) is located in coverage of a macro base station, and TPs formed by different RRHs and the macro base station share a same cell identifier. However, the macro base station and each of the RRHs generally have different CSI RS configurations. That is, in this case, a same cell identifier corresponds to multiple CSI RS configurations. Because the macro base station and each of the RRHs correspond to different channel conditions and interference conditions, an eNB needs to configure a proper CSI RS related to a same cell identifier for a UE instead of configuring only according the cell identifier, so that the UE can select a proper TP for access.
In addition, for the heterogeneous network deployment scenario, a cell specific reference signal CRS (Cell specific Reference Signal, CRS) faces a similar CRS port selection problem caused by that an RRH or a macro base station is geographically separately configured.